In Reply: Management of Major Arterial Injuries: A Critical Complication of Endoscopic Endonasal Surgery

To the Editor: We would1 like to thank the authors for their interest in these comments. Abou-Al-Shaar et al contributed to the field of endoscopic endonasal surgery (EES), particularly regarding the management of major arterial injuries, through their previous publications.2-4 The terms “high-flow” and “low-flow” bleeding were not intended to redefine arterial physiology but to describe the intraoperative bleeding pattern observed during surgery. “High-flow bleeding” referred to explosive hemorrhage from full-thickness arterial injury that rapidly obscured the surgical field and was difficult to control even with large-caliber suction devices. By contrast, “low-flow bleeding” referred to hemorrhage from the adventitial layer of the vessel wall, indicating a partial wall injury. We provided intraoperative videos illustrating high-flow bleeding. As an example of low-flow bleeding, the intraoperative video of the clival chordoma case shown in Figure 1A from the original manuscript1 demonstrates bleeding from the paraclival carotid artery following resection (Video 1). {"href":"Single Video Player","role":"media-player-id","content-type":"play-in-place","position":"float","orientation":"portrait","label":"VIDEO.","caption":"Intraoperative video illustrating a case of clival chordoma (Figure 1A from the original manuscript), demonstrating low-flow bleeding from the paraclival segment of the internal carotid artery following tumor resection","object-id":[{"pub-id-type":"doi","id":""},{"pub-id-type":"other","content-type":"media-stream-id","id":"1_uk5ggpkx"},{"pub-id-type":"other","content-type":"media-source","id":"Kaltura"}]} Although many studies address the management of major arterial hemorrhage, no single, universally accepted protocol exists. Optimal strategy depends on hemorrhage location and severity, underlying pathology, and the patient's hemodynamic status. Reported hemostatic options include oxidized regenerated cellulose, muscle grafts, fibrin glue, gelatin–thrombin matrix sealants, bipolar cautery, ipsilateral carotid compression, nasal/surgical packing, surgical clipping, endovascular embolization with balloon/coil, and stent placement.5 Outcomes hinge not only on technical execution but also on multidisciplinary readiness. Real-time coordination with anesthesia, active maintenance of hemodynamic stability, and advance notification of the endovascular team in patients at high risk of arterial injury are critical components of successful management. We carefully reviewed the authors' comments regarding the use of gelatin–thrombin–based hemostatic agents (Floseal®, Surgifoam™) in arterial injuries. These agents were not used as the primary treatment for high-flow bleeding but rather to achieve temporary visual control and local hemostasis. They were never solely relied upon for high-flow bleeding; however, in low-flow bleeding, they served as the primary hemostatic measure. Once bleeding was controlled, patients were referred for endovascular evaluation (digital subtraction angiography, stenting, balloon, and coil embolization). We are not entirely opposed to the authors' view that gelatin–thrombin-based agents, owing to their injectable and semifluid nature, may carry a risk of distal embolization through intraluminal migration when applied to active arterial bleeding. This potential for thromboembolic complications was also discussed in our study. However, we do not agree that these agents should be strictly avoided in severe hemorrhage. Supporting evidence exists in the literature—for instance, Cappabianca et al6 reported multiple Floseal applications for internal carotid artery rupture without any embolic complications. Similarly, a 2021 report described successful use of this agent for a basilar artery injury, achieving effective hemostasis without any embolic events.7 In addition, during glioblastoma resection, a gelatin–thrombin matrix was used to control bleeding from the middle cerebral artery, with no embolic complications reported.8 Similar observations have been reported in other surgical fields. For instance, a 2017 thoracic surgery study used a gelatin–thrombin matrix for 18 pulmonary artery injuries without any early or late postoperative embolic events.9 These data, of course, do not conclusively demonstrate that gelatin–thrombin matrix agents are entirely safe for arterial bleeding. Although several studies have reported no embolic complications with their use, others have documented embolic events following their application.10-12 Therefore, as no clear contraindication exists for the use of these agents in arterial bleeding, our 15 case EES series contributes to the literature by demonstrating that the gelatin–thrombin matrix used caused no embolic complications in any case. As the authors noted, using crushed muscle grafts or applying compression with cottonoid patties supported by oxidized cellulose, are well-described and effective hemostatic techniques. Similarly, when hemostasis was not achieved with agents, temporary compression with cottonoid and gauze packs in the sphenoid sinus was applied. The patient was transferred for endovascular treatment and subsequently was brought back to surgery for removal of the packs. However, caution is advised when using muscle tissue or cottonoid, as excessive pressure, although effective for hemostasis, may cause partial or complete arterial occlusion or pseudoaneurysm formation, particularly after endovascular recanalization.13-15 Even when bleeding seems controlled, ischemic complications may occur from reduced cerebral perfusion; thus, the duration and intensity of compression must be precisely regulated. Similarly, sphenoid sinus packing may mask ongoing carotid bleeding by reducing visible hemorrhage and creating a false impression of hemostasis. Major arterial bleeding in EES, although rare, is one of the most serious complications that can lead to devastating consequences. The management of this complication is a multifactorial and dynamic process that cannot be reduced to a single protocol or standardized approach. Successful control of bleeding depends on numerous parameters, including the location and severity of the hemorrhage, the specific arterial segment involved, the patient's hemodynamic status, and the level of coordination within the surgical team. Numerous surgical techniques and adjunctive agents have been described, each offering specific advantages in different clinical contexts. Our 15 case series provides a meaningful contribution to the literature by highlighting the outcomes of the techniques and approaches we used when confronted with this rare but critical complication. Our goal is to share our experience in managing such cases to enhance patient safety and provide a guiding perspective for surgeons who may encounter similar situations.